Sander



HARRIS Feb, Z 195G SANDER Filed Nov. 50, 1946 4 INVENTOR Fox-55 .765 s TTORNEYS Patented Feb. 7, 1950 SANDER Forist Harris, Merced, Calif., assignor to Brunswick-Balke-Collenden.Company, Chicago, 111.,

a corporation of Delaware Application November 30, 194.6, Serial No. 713,278

Another object of the invention is to provide a floor sanding machine wherein the, floor engaging sandpaper is reciprocated in thedirection of travel to avoid the marking of the floor which results from the useof rotary type sand.- ing machines; the sandpaper lying flat on the floor at all times during operation of the machine, and the entire weight of the latter being imposed on said paper. In this manner a very accurate and fine appearing finish may be applied to the fioor.

It is also an object of this invention to provide'a floor sanding machine, as above, wherein the floor engaging sandpaper, in addition to being reciprocated in the direction of travel, is simultaneously oscillated in a horizontal planeso as to accomplish a very effective sanding action.

An additional object of the invention is to provide a floor sanding machine which. includes a main frame having an electric motor mounted thereon, longitudinally spaced, fiat sandpaper blocks below'the main frame in horizontal alinement, the blocks being secured to the frame for limited longitudinal reciprocation and supporting said frame, and means between the motor and blocks operative to so reciprocate the latter.

A further object of the invention is to provide a practical sander, and one which will be ex ceedingly effectivefor the purpose for which it is designed.

These objects are accomplishedby means of such structure and relative arrangement of parts as will fully appear by a perusal of theifollowing specification and claims. I

In the drawings: I

Fig. 1 is a side elevation of the floor sanding machine in'position for use. 1 Fig; 2 is a rear end view of themachine in position for use.

.Fig. 3 is a diagrammatic view of the eccentric assembly. I1 I 'Fig. 4 is a fragmentary plan view of one of the throw-over latches illustrating the manner of its engagement with the adjacent leg of the bailtype handle. I

Referring now more particularly tothe characters of reference on the drawings,"the improved floor sanding machine comprises "arigid main frame, indicated generally at I said main frame being of inverted U-shape and extending transversely of the direction of travel:

and it is-an object 9 Claims. (01'; 51-115) A pair of mounting yokes 2 of inverted U-shape are attached at the top, by bolts 3, in transversely spaced relation, and at right angles to the cor responding part of the main frame I. The mounting yokes 2 are attached to the main frame I! in symmetrical relation, i. e. projecting ahead and to the rear of said main frame equal distances.

, Below the assembly of the main frame I and mounting yokes 2 the machine includes a pair of flat, horizontal sandpaper blocks 4 which are rectangular in plan but elongated transversely of the machine. The sandpaper blocks 4 are alined lengthwise of the direction of travel and are spaced apart so that one block is disposed below the forward pair of legs of the mounting yokes 2, while the other block is disposed below the rearwardpair of said legs. Such pairs of legs approach closely to the corresponding blocks substantially centrally between the forward and rearward edges of the same, and are there connected by bolts 5 with cross bars 6 secured be tween upstanding flanges I on top of said blocks 4. Resilient or cushion washers 8 are interposed between the bolts 5 and the parts connected thereby.

The mounting yokes 2 are of spring steel so that the sandpaper blocks are capable of limited reciprocating movement horizontally in the direction of travel.

An electric motor 9 is mounted in connection with, and depends from, the top of the rigid main frame I, and drives a cross shaft Ill, journaled in said frame, through the medium of an endless belt and pulley unit I l.

Adjacent each end of the cross shaft Iii, and in alinement with corresponding legs of the mounting yokes 2, said shaft is fitted with a pair of eccentric units, the units of each pair being indicated at [2 and I3, and each is attached to a connecting rod M. The connectingrods M of each pair of eccentric units extend in opposite directions through adjacent legs of the mounting yokes 2, bein secured to said legs by nuts l5 threaded on said rods on opposite sides of the legs. Resilient or cushion washers l6 are disposed on the rods l4 between the nuts i5 and connected legs of the yokes 2.

The bottom surface of each sandpaper block 4 is roughened, as at IT, and a sheet of sandpaper IS lies flat against said surface transversely of the blocks 4, turning upwardly at the ends of the latter, as shown in Fig. 1. The roughened bottom surface of the sandpaper block tends to prevent displacement of the paper of the cross shaft N3, the eccentric units l2 rreshort stroke, but at substantial speed; the cush- This -reciprocation 'of the sandpaper blocks is through "a relatively ion washers 8 and i6 tending to "absorb .nny

abrupt action and minimizing vibration. The reciprocation of the sandpaper blocks 4 is of course possible, as previously explained, for the reason that the mounting yokes 2 are -'of spring steel.

Most eiiicient operation ofthe machine is accomplished when the eccentric units 12 and 13 of each pair are opposed or set 180apart, with the corresponding eccentrics-of the opposite end pairs '(i. e. eccentrics-l-2l2, and l3l3) set to run 90 apart.

With this arrangement of the eccentrics the sandpaper blocks not only reciprocate, in opposition, lengthwise of the direction 'of travel, but they also simultaneously oscillate in a horizontal plane, thus accomplishing a rapid, efifective, and accurate sanding action. Further, as the reciprocation is "in the direction of travel, or lengthwise of the grain of the floor, as in -'a bowling alley, no undesirable floor marking occurs, as is the casewith rotary type-sanding'machines.

Also, the machine is quite efiicient forlthe'reason that the entire weight .thereof bears on the sandpaper blocks 4 when such machineis in operation.

jDust removal from the machine is accomplished as follows:

Hoods 2| are mounted along the outertransverse edges of the sandpaper blocks '4, andanother hood 22 spans between adjacent transverse edges of said blocks, the hood '22 being flexible to permit of relative movement between the blocks as the machine operates. Suction hoses 23 .lead from the above described hoods upwardly .to .the intake of a suction .fan

unit 24 mounted in the main :frame I. The suction fan unit,2.4 is driven from the cross shaft ID by an endless belt and pulley unit 25. The diechargeifiof the suction fan unit 24 delivers to a dust carry-off hose 2'! Whichleads to a suitable bag, or other dust receptacle. I v

The machine is guided, when in operation, .by a swinging or bail-type handle 28 pivoted, as at -29, :to opposite ends of the .rigid main ,frame 2'. For transportof the machine the handle :28 .may be locked in a vertical position by throw-over latches -30 hingedly mounted on topof the main frame I, and being forked, as at 31, .to straddle the adjacent leg of the handle 12.8 when .it isin said upright position.

To facilitate movement of the machine, when not 'in use,.along a ncur a pair :of .rigid arms '32 are 'fixed :in connection with ppposite ends :of the rigid main frame l and-extend *rearwardly to ;a termination beyond the rearmost Jsanding block. At their routerends the arms 132 are fitted with rollers 33. To so move the machine the bail-type handle 28 is locked up in its vertical position, and the machine then rocked rear- Wardly by said handle until the rollers 33 come into floor engagement and the sandpaper blocks 4 rise free of the floor. Thereafter the machine can be readily rolled along the floor from place .to place.

From theforegolng descripti'oniitwill be readily seen that there has been produced such a de- -vice as substantially fulfills the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and-preferred construction of the d'evice stillin'practice such deviations from such detail maybe resorted to as do not form a departurezfromrthespirit of the invention, as described by the appended claims.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

11. A :floor 'sanding machlne comprising "a main frame, a ;mounting yoke "of inverted U-shape secured to themain frame with the yoke legs spaced apart in the direction o'f'tra'vel, 'aisandpaper block disposed-below each yoke leg, means securing each block :to -the .corresnondingzyoke leg, .said legs 'being of spring rmetal whereby the blocks are mounted for limited rec'ipro'catingrmotion in said direction, an welectricmotoron the main .frame, and means driven by the motor operative to horizontally reciprocate the blocks;- said meansincluding'a motor-driven crossshait, eccentric .units *on 'the :shaft corresponding to the yoke legs, and connecting rods :between the eccentric units and said corresponding .legs,

.2. A floor sanding machine comprising :a :main frame, :a :mounting :yoke :of inverted U-shape secured to the ;main frame with :the: yoke legs spaced :apart :in :the direction of travel, 5a, sandpaper block disposed lbElOW each-yoke *leg,: me'ans securing each :block to the cool-responding yoke leg,.=sai'd .legs=being .o'fspring metal whereby the blocks are :mounted .for limited reciprocating motion said direction, ran electric .motor on the mainframe, and meansadriven by :the motor operative to horizontally reciprocate the blocks; said :means including 1 a motor-driven cross shaft, eccentric units on the shaft corresponding to the yoke legs, and connecting rods between'the eccentric units and said corresponding *legsthere being cushion imeans interposed between each connecting rod and corresponding leg.

3. A floor sanding machine comprising a main frame, :a mounting ,yoke of inverted U-shape secured. .to the main frame with the yoke legs spaced apart in .the-direction-of-travel, asandpaper block disposed below iea'ch yoke leg, means securing each block to the corresponding yoke leg, said =1egs being of spring metal whereby the blocks are mounted for limited reciprocating motion in said direction, an-electric motor on the main frame, and means driven by ,:the='motor operative to :lmrizontally reciprocate :the blocks; said means including a motor-driven cross-shaft, eccentric -units ion the :shaft corresponding to the ,yoke legs, and connecting .rods :between .the eccentric unitsandzsaid -.'corresponding :legs, there being cushion means interposed between each connecting :rod :and corresponding .leg, and between each leg r-andtthe corresponding block. l 14. Ajloor sanding machine comprising a main frame of :inverted U-ishapedisposed transversely of the ziirection 'of -itra vel, a .pair 'of inverted U-shape mounting ryokes secured to the top :of

the main frame with the legs of each yoke spaced lengthwise of said direction, a flat, horizontal sandpaper block disposed below the front and rear pairs of the yoke legs, said legs being of spring metal, means securing each block to the corresponding pair of legs, an electric motor mounted on the main frame, and motor driven means operative to horizontally reciprocate the blocks in said direction.

5. A fioor sandingmachine comprising a main frame of inverted U-shape disposed transversely of the direction of travel, a pair of inverted U-shape mounting yokes secured to the top of the main frame with the legs of each yoke spaced lengthwise of said direction, a fiat, horizontal sandpaper block disposed below the front and rear pairs of the yoke legs, said legs being of spring metal, means securing each block to the corresponding pair of legs, an electric motor mounted on the main frame, and motor driven means operative to horizontally reciprocate the blocks in said direction; said motor-driven means comprising a cross shaft journaled in connection with and extending between the legs of the main frame, driving connections between the motor and shaft, an eccentric unit on the shaft corresponding to each yoke leg, and a connecting rod between each of the eccentric units and the corresponding yoke leg.

6. A floor sanding machine comprising a main frame of inverted U-shape disposed transversely of the direction of travel, a pair of inverted U-shape mounting yokes secured to the top of the main frame with the legs of each yoke spaced lengthwise of said direction, a fiat, horizontal sandpaper block disposed below the front and rear pairs of the yoke legs, said legs being of springmetal, means securing each block to the corresponding pair of legs, an electric motor mounted on the main frame, and motor driven means operative to horizontally reciprocate the blocks in said direction; said motor-driven means comprising a cross shaft journaled in connection with and extending between the legs of the main frame, driving connections between the motor and shaft, an eccentric unit on the shaft corresponding to each yoke leg, and a connecting rod between each of the eccentric units and the correspondingyoke leg, the pair of eccentric units corresponding to the legs of each block being fixed on the shaft with one of said pair leading the other whereby to cause horizontal oscillation of such block simultaneously with reciprocation thereof.

7. A floor sanding machine comprising a main frame of inverted U-shape disposed transversely of the direction of travel, a pair of inverted U-shape mounting yokes secured to the top of the main frame with the legs of each yoke spaced lengthwise of said direction, a-flat, horizontal sandpaper block disposed below the front and rear pairs of the yoke legs, said legs being of spring metal, means securing said block to the corresponding pair of legs, an electric motor mounted on the main frame, and motor driven means operative to horizontally reciprocate the blocks in said direction; there being suction hoods adjacent the edges of the blocks, a suction fan unit on the main frame driven by the motor, suction conduits between the hoods and fan unit, and a discharge conduit leading from said fan unit.

8. In a sanding machine the combination of: a main frame, a motor mounted on the main frame, an abraidingblock, a hanger connected to the block at each end thereof and to the frame and mounting the block for simultaneous reciprocating and oscillating movement in a horizontal plane relative to the frame, and a separate connection between the motor and each of the hangers and operative to impart a differential reciprocating movement thereto.

9. In a sanding machine the combination of a main frame, a motor mounted on the main frame, an abrading block, means supporting the block from the frame, a driving member connected to the block at each end thereof, and connections between the motor and driving members, such connections being effective to impart a differential reciprocating movement to said driving members upon operation of the motor.

FORIST HARRIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,123,097 Clemons Dec. 29, 1914 1,175,245 Dennis Mar. 14, 1916 1,550,102 Schlueter Aug. 18, 1925 2,054,458 Arge et al Sept. 15, 1936 2,113,694 Kohle Apr. 12, 1938 2,175,237 Young Oct. 10, 1939 2,202,072 Wilson May 28, 1940 2,205,492 Reid June 25, 1940 2,276,534 Burleigh Mar. 17, 1942 2,280,446 Nyman Apr. 21, 1942 FOREIGN PATENTS Number Country Date 739,689 France Jan. 16, 1933 

